The town was planned on a gridiron pattern with the church occupying a dominant two-acre site near the centre. It was planned on a grand scale and work started in 1288 to erect a magnificent Gothic edifice, with a chancel and choir, two side chapels, a central tower, transepts and a great nave.

Building stone came from Caen in Normandy, marble from the west of Sussex and timber rafters made of sound Sussex oak. Highly skilled stonemasons worked on the carvings which include handsome sedilia in the chancel and side chapel. Three effigies of polished marble – once thought to have been rescued from the church in Old Winchelsea – were placed on the north side in memory of an unknown warrior, his wife and son, possibly the Godfrey family.

The first of the two chantries on the south side was endowed in 1312 by Stephen Alard to contain a tomb of supreme workmanship in memory of Gervase Alard, Admiral of the Western Fleet, probably Stephen’s father. The stone effigy is in full armour with raised hands to enclose a heart and a lion crouching at the feet. Two large angels supported the double cushion on which the head rests. A marginal inscription promises fifty days of pardon for those who pray for his soul. The delicately carved arch of the recessed canopy springs from the heads of King Edward I and his second wife, Margaret. The tomb provided the background for Sir John Millais’ painting ’L’Enfant du Regiment.’

The second monument is of a later date, with the arch springing from the heads of Edward II and Queen Isabella, sometimes known as ‘the she-wolf of France.’ It is reputed to be the tomb of Stephen Alard himself, who became Admiral of the Cinque Ports and the Western Fleet.

The centre of each canopy is surmounted by the head of a Green Man, a prominent pagan figure, associated with tree worship from at least as early as 500BC.